We eat in the dining room on the first and last night and otherwise always eat in the Windjammer so we can go at our own time and in comfortable dress.
The food is as good as the main dining rooms, and there is a much wider selection. The only difference is you select and serve yourself. They do have some wine and beverage service, waiters come around.
I have eaten dinner in the Windjammer; its a buffet like people mentioned. the service is good, they have pretty much the same food as the main dining room, and u don't have to get dressed up. I have gone there when I don't want to take the time to get all dressed up for dinner.
Freedom of the Seas Dec 11
Allure of the Seas: Jan 11
Voyager of the Seas: May 09
Splendour of the Seas: May 07
Explorer of the Seas: Jan 04
Majesty of the Seas Jan 99